Performance of a Set of Eggplant (Solanum melongena) Lines With Introgressions From Its Wild Relative S. incanum Under Open Field and Screenhouse Conditions and Detection of QTLs

Abstract

Introgression lines (ILs) of eggplant (Solanum melongena) represent a resource of high value for breeding and the genetic analysis of important traits. We have conducted a phenotypic evaluation in two environments (open field and screenhouse) of 16 ILs from the first set of eggplant ILs developed so far. Each of the ILs carries a single marker-defined chromosomal segment from the wild eggplant relative S. incanum (accession MM577) in the genetic background of S. melongena (accession AN-S-26). Seventeen agronomic traits were scored to test the performance of ILs compared to the recurrent parent and of identifying QTLs for the investigated traits. Significant morphological differences were found between parents, and the hybrid was heterotic for vigour-related traits. Despite the presence of large introgressed fragments from a wild exotic parent, individual ILs did not display differences with respect to the recipient parent for most traits, although significant genotype × environment interaction (G × E ) was detected for most traits. Heritability values for the agronomic traits were generally low to moderate. A total of ten stable QTLs scattered across seven chromosomes was detected. For five QTLs, the S. incanum introgression was associated with higher mean values for plant- and flower-related traits, including vigour prickliness and stigma length. For one flower- and four fruit-related-trait QTLs, including flower peduncle and fruit pedicel lengths and fruit weight, the S. incanum introgression was associated with lower mean values for fruit-related traits. Evidence of synteny to other previously reported in eggplant populations was found for three of the fruit-related QTLs. The other seven stable QTLs are new, demonstrating that eggplant ILs are of great interest for eggplant breeding under different environments.

Comparative Transcriptome Analysis Reveals Key Genes and Pathways Involved in Prickle Development in Eggplant

“…Genetic analysis revealed that a major QTL located in chromosome 6 of eggplant is responsible for prickliness variability [13,14,44], and this locus was recently fine-mapped to a 133 kb interval [4]. Our transcriptome analysis indicated that four genes were significantly differentially expressed during prickle development, including three enzymes and one TF ( Supplementary Table S11).…”

“…Transcriptome analyses in raspberry and S. viarum further identified several transcription factors (TFs) that may play important roles in prickle development [10,11]. In eggplant, several quantitative trait loci (QTLs) for prickle have been identified on chromosomes 2, 6, 7 and 8 [3,[12][13][14]. A recent study has genetically mapped a Pl locus on chromosome 6, and developed a 0.5 kb presence/absence variant marker for the marker-assisted selection of prickleless eggplant [4].…”

The Role of Vegetable Genetic Resources in Nutrition Security and Vegetable Breeding

“…Apart from drought tolerance, S. incanum is also known to have a high content of bioactive phenolic compounds [94], as well as resistance to some diseases [95]. Open-field and screenhouse evaluations of the eggplant IL population mentioned above revealed that desirable traits such as lack of prickles and yield did not undergo considerable changes in most ILs despite the introgression of relatively large fragments from the wild exotic parent [96]. Ten stable QTLs distributed across seven chromosomes were detected, and three of the fruit-related QTLs appeared to be syntenic to other ones previously reported in eggplant populations.…”

Production and characterization of inter and intraspecific hybridization eggplant

“…However, Kaushik et al (2016) reported small fruit size of the hybrids developed by crossing cultivated eggplant with Solanum incanum. Mangino et al (2020) evaluated the performance of 16 introgression lines (ILs) containing chromosomal segments of S. incanum and reported improved vigour in the ILs but exhibited low value of various fruit related parameters. Availability of large number of accessions (167) of S. incanum (Taher et al, 2017) offers to select the best performing one for distant hybridization.…”

“…We tried to describe the characteristics of intraspecific and interspecific hybrids between S. melongena x S. melongena and S. melongena x S. incanum and found positive gain in fruit size and fruit yield per plant compared to the parents. Given the high quality (phenolic contents) of S. incanum, and tolerance to drought and resistance to a few diseases (Prohens et al, 2013: Mangino et al, 2020 as well as suitability as rootstock (Gisbert et al, 2011), these materials may be of great interest for developing a new generation of eggplant varieties adapted to climate change and tolerance to drought and heat stress.…”